# Writing a sequence in terms of n.

1. Dec 10, 2011

### mtayab1994

1. The problem statement, all variables and given/known data

given: Vn+1=Vn*cos(pi/2^(n+2))

2. Relevant equations

Write a sequence Vn in terms of n

3. The attempt at a solution

we substitute n with n-1 and we get:

V(n-1)+1= Vn-1*cos(pi/2^(n-1+2))

Vn=Vn-1*cos(pi/2^(n+1)

Is this correct?

Last edited: Dec 10, 2011
2. Dec 10, 2011

### SammyS

Staff Emeritus
Yes: Vn = Vn-1*cos(π/2(n+1)) .

3. Dec 10, 2011

### mtayab1994

Alright it was an extra credit question in class just wanted to make sure if it was correct. Thank you very much.

4. Dec 10, 2011

### mtayab1994

Off topic question, do u know any good latex software i can't used the stuff given in the forums.

5. Dec 10, 2011

### SammyS

Staff Emeritus
I mostly use the LaTeX from the Forums.

To check my code I sometimes use mimeTeX online.

Do a search in these Forums.

6. Dec 10, 2011

### mtayab1994

Alright really appreciate it.

7. Dec 10, 2011

### LCKurtz

8. Dec 10, 2011

### mtayab1994

Yea i have them, but when i type up something in there and I try putting it up in here it comes up all weird.

9. Dec 10, 2011

### LCKurtz

Oh, I didn't understand that's what you wanted to do. What problem are you having using the forum TeX tools for the forum?

10. Dec 10, 2011

### mtayab1994

It's not a 'problem' but sometimes when I want to type something in it doesn't come up how I want it. This is an example with Lyx:

U_{n+1}=V_{n}+U_{n}

11. Dec 10, 2011

### LCKurtz

I'm confused. That is an example of what with Lyx?$$U_{n+1}=V_{n}+U_{n}$$ displays OK here with tex tags.

12. Dec 10, 2011

### mtayab1994

Yea i can't get it to come out like that how can i do it?

13. Dec 10, 2011

### LCKurtz

You have to enclose tex expressions with tex or itex tags. They are like the  or \$ tags in regular tex. Right click on the expression to see the source.

 Woops, that doesn't show the tags. Start to reply with a quote to the post with the tex and you will see the tex tags. It's like this: [tox]Put your tex here[/tox] and use tex instead of tox. (If I use tex you won't see the tags).

Last edited: Dec 10, 2011
14. Dec 10, 2011

### mtayab1994

$$U_{n+1}=V_{n}+U_{n}$$

alright i got it to work thanx a million!

15. Dec 10, 2011

### LCKurtz

Yep. You can use itex for inline and you can preview your posts before you submit them to see it's all OK.